The marketing attack follows Intuit's being forced to reverse its taking schedules C, D, E, and F out of TurboTax Deluxe and putting them in the higher priced TurboTax Premier. Then there is the widely reported fraud affecting TurboTax state efilings in several states, a problem now being pursued by the Federal Bureau of Investigation.

Block said the offer on switching to the company's paid preparation services is being offered for a limited time, although its press release did not state when the offer ends. The offer began on February 15.

To receive the discount, taxpayers must bring tax preparation receipts from last year to a Block office. The offer covers individual and business, federal and state tax returns filed in 2014 of $150 or more. Returns valued less than $150 will be charged $75.